Nokia launched its latest Lumia devices at Mobile World Congress this week. While many were hoping the company would unveil a 41-megapixel PureView device, or a Windows tablet, Nokia opted to flesh out its range of Lumias and give us an early look at where it's heading for 2013. With 12 Lumia products launched, excluding variants, Nokia's strategy is clear: offer colorful Lumia devices at various price points by pushing high-end features down the range. Nokia's Lumia series is broad and complete (for now), but Microsoft has to help Espoo catch the competition.

Nokia's high-end flagship is the Lumia 920. Launched in early November, the 920 has helped boost Lumia sales to their highest point, 4.4 million, in the most recent quarter, but supply issues have dampened the launch slightly. Nokia CEO Stephen Elop has previously admitted that the company was "very deliberate" and "thoughtful" about Lumia supplies in a move that appears to be designed to avoid oversupply issues.

Windows Phone still has to beat BlackBerry

Nokia's upcoming quarter may include some sales of the new Lumia 720 and 520 devices, depending on when they're made available in March, but it will also be the most significant part of the Lumia's short history to judge how well Nokia's strategy is playing out. It's very much Nokia vs. BlackBerry in the battle to decide which ecosystem will secure the third spot. BlackBerry has been on a steady decline over the past year, while Windows Phone has nearly doubled its market share. That boost has relied heavily on Nokia's range of devices over the course of 2012, as the Finnish company continues to prop up the Windows Phone market.

Data from AdDuplex, a firm that tracks 215 Windows Phone apps, shows that Nokia's investment in its low- to mid-range devices is where it's growing volume. The Lumia 710, Lumia 800, and Lumia 610 were the most popular Windows Phone devices worldwide during a day of data gathering in early January. The recently launched Lumia 520 and 720 push Windows Phone 8 price points even lower, so these devices are bound to help grow Microsoft's mobile market share and Nokia's revenue. Windows Phone has shown slow signs of growth over its two year tenure, with short boosts of life around big products, but it's now time for Nokia to shift gears and focus on the high-end.

A series of high-end Lumias are on the horizon

Nokia is planning to launch a number of new high-end Lumias over the coming months. While the 720 and 520 will take care of he mid- to low-range, Nokia's other strategy of carrier exclusives will continue in 2013. The Verge has previously detailed Nokia's plans for a 41-megapixel Lumia PureView device, codenamed EOS, that will debut as an AT&T exclusive. Nokia is also preparing a Lumia 928 for Verizon, codenamed Laser. A switch away from polycarbonate designs towards an aluminum body will take place with a new Catwalk device too that will debut on T-Mobile in the summer. Nokia's plans for the high-end are aggressive and underline the company's focus on Windows Phone.

While Microsoft has been talking up Windows Phone for what feels like years, 2013 is the biggest test of how the platform will fare. If it can secure 10 percent of market share, with a third place spot, it would help push the focus from developers on Windows Phone. Microsoft still lacks some of the big games and apps that thrive on rival platforms, despite promises they would arrive. Microsoft's quiet approach to Windows Phone 8 with a roadmap of smaller updates will bring additional features that benefit Nokia too, but the apps are still key and affect a buyer's decision.

Time to turn it up to 11

Windows Phone is still in a catch-22 position. It needs developers to create apps and push the ecosystem, but developers need to see signs of life and device sales until they're able to commit resources and money to another platform. It's really time for Windows Phone to prove itself this year, and for Microsoft to show it can add significant updates over 2013. Windows Phone 8 is a good base for Microsoft to continue its differentiation with new features, but the company has to address some shortcomings.

Notifications are a big weakness on Windows Phone, as are the general customization options versus Android. Xbox Music was a good introduction for Windows Phone 8, but playlist management needs to be improved on the desktop and phone. Little things like rotation lock, separate volume for notifications and video / audio playback, folder support for apps, and a universal search service similar to Windows 8 all need to be added. Nokia is supplying the hardware numbers, but Microsoft needs to crank its platform to 11. It's about time Windows Phone reached maximum volume.